Document usage of pactbroker.providerBranch with the matching branch selector

Author: timvahlbrock

docs/system-properties.md

@@ -39,7 +39,7 @@ Theses are all the system properties used by Pact-JVM
 | pactbroker.enableInsecureTls                           | Verification (JUnit, JUnit 5) | true, false             | n    | y    | n            | Enabling insecure TLS by setting this to true will disable hostname validation and trust all certificates. Use with caution.                                                                                                                                                                                                                                                      |
 | pactbroker.enablePending                               | Verification (JUnit, JUnit 5) | true, false             | n    | y    | n            | If the pending pacts feature should be enabled when fetching pacts to verify. When this is set to true, the provider tags or provider branches property also needs to be set (pactbroker.providerTags or pactbroker.providerBranch).                                                                                                                                              |
 | pactbroker.providerTags                                | Verification (JUnit, JUnit 5) | tag names               | y    | y    | n            | Provider Tags to use to evaluate pending pacts when fetching pacts to verify.                                                                                                                                                                                                                                                                                                     |
-| pactbroker.providerBranch                              | Verification (JUnit, JUnit 5) | branch name             | y    | y    | n            | Provider Branch to use to evaluate pending pacts when fetching pacts to verify.                                                                                                                                                                                                                                                                                                   |
+| pactbroker.providerBranch                              | Verification (JUnit, JUnit 5) | branch name             | y    | y    | n            | Provider Branch to use to evaluate pending pacts when fetching pacts to verify. Also used as the provider branch name to match when using the matching branch selector.                                                                                                                                                                                                           |
 | pactbroker.includeWipPactsSince                        | Verification (JUnit, JUnit 5) | ISO date (YYYY-MM-DD)   | n    | y    | n            | The earliest date WIP pacts should be included (ex: YYYY-MM-DD). If no date is provided, WIP pacts will not be included.                                                                                                                                                                                                                                                          |
 | pact.verification.reportDir                            | Verification (JUnit, JUnit 5) | Directory name          | n    | y    | n            | Sets the directory to write any configured verification reports to.                                                                                                                                                                                                                                                                                                               |
 | pactfolder.path                                        | Verification (JUnit, JUnit 5) | Directory name          | n    | y    | n            | Directory to fetch pacts from when using the folder loader.                                                                                                                                                                                                                                                                                                                       |